Regiospecific functionalization of methyl C-H bonds of alkyl groups in reagents with heteroatom functionality
Regiospecific functionalization of methyl C-H bonds of alkyl groups in reagents with heteroatom functionality
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DOI：
10.1021/ja044933x
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发表时间：
2004-12-01
影响因子：
15
通讯作者：
Hartwig, JF
中科院分区：
文献类型：
--
作者：
Lawrence, JD;Takahashi, M;Hartwig, JF
我们报告了具有现有功能的分子中饱和末端 C−H 键的区域特异性、铑催化的硼基化。使用过量的有机底物并作为限制试剂获得了中等至良好的产率。三烷基胺、受保护的醇、受保护的酮和氟代烷烃的硼基化发生在空间位阻最小的甲基上。还进行了一些反应来探究电子对烷基硼化的影响。这些反应表明硼化反应优先发生在最缺电子的甲基上。还开发了进行 C-H 键串联硼基化以及将所得硼酸酯转化为醇、烷基芳烃和烷基三氟硼酸酯的方法。
We report the regiospecific, rhodium-catalyzed borylation of saturated terminal C−H bonds in molecules with existing functionality. Moderate to good yields were obtained with the organic substrate in excess and as limiting reagent. The borylations of trialkylamines, protected alcohols, protected ketones, and fluoroalkanes occurred regiospecifically at the methyl group that is least sterically hindered. Reactions were also conducted that probed electronic effects on the alkyl borylation. These reactions showed that the borylation occurred preferentially at the methyl group that is most electron-deficient. Methods to conduct tandem borylation of C−H bonds and conversion of the resulting boronate esters to alcohols, alkylarenes, and alkyltrifluoroborates were also developed.